Quantum Dot−Carrier Peptide Conjugates Suitable for Imaging and Delivery Applications

Abstract

We developed multifunctional fluorescent nanoparticles suitable for the nonviral delivery of negatively charged molecules like RNA. Therefore, we incorporated the recently developed branched hCT-derived carrier peptide hCT(18-32)-k7 on the surface of luminescent quantum dots (QDs). Besides detailed characterization of our QD-peptide conjugates concerning stability, toxicity, and uptake mechanism. we used them for efficient RNA delivery into different cell lines. The results of our studies indicate the involvement of more than one endocytotic uptake pathway in the internalization process. Furthermore, we could show that the QD-peptide bioconjugates exhibit no effect on cell viability and possess high stability inside living cells. The efficacy of our newly designed constructs for oligonucleotide drug delivery is highlighted by the successful intracellular transport of Cy-3 labeled RNA. Moreover, by using the chemotherapeutic chloroquine the efficient release of the assemblies out of endosomes was demonstrated. These results prove that our multifunctional platforms are versatile tools for diagnostic and therapeutic imaging purposes applicable for biologically active siRNA or aptamer sequences.

Multi-functional liposomes having temperature-triggered release and magnetic resonance imaging for tumor-specific chemotherapy

“…Recently, efforts have been made to provide imaging functions to various types of carriers by incorporating various types of imaging probes, such as quantum dots [15][16][17], 5 magnetic iron oxide nanoparticles [11,12,18,] and radionuclide 18 F [19,20] have been incorporated to drug carrier materials for fluorescence imaging, magnetic resonance imaging (MRI), and positron emission tomography (PET) imaging, respectively. Among them, MRI is advantageous from the view points of image of high resolution and no exposure to radiation.…”

Specific labeling with potent radiolabels alters the uptake of cell‐penetrating peptides

“…10 Since then, very promising branched structures have been developed and have served for the delivery of plasmid DNA as well as nanoparticles. 11,12 The side sequence of these branched peptides contains positive charged amino acids for complexation of negatively charged DNA or RNA molecules. However, one crucial prerequisite for a successful radionuclide labeling is that the nature of the active compound is not affected by the label.…”

Quantum dots, lighting up the research and development of nanomedicine

“…SiRNA attached to the particle by disulfide cross-linkers showing greater silencing efficiency than when attached by a nonreducible thioether linkage. Walther et al 77 developed fluorescent delivery system for oligonucleotide drug by incorporating branched hCT-derived carrier peptide hCT (18-32)-k7 on the surface of QDs, which could successful intracellular transport Cy3 labeled RNA and exhibit no effect on cell viability.…”